An acoustic guitar.
Primarily used to "wow" people with their mad emo skills.
"Damnit, that loser brought his emo box to your party."
A box that most people have. It is for when the person is feeling extremely sad or just unwilling to cooperate. They go and hide in it. Somehow it manages to hold even the largest person.
Girl: Dude, you suck!
Dude: ;_; *hides in emo box*